Dioxin in the fat of breast milk measured in women 30 days after childbirth averages 22.2 picograms per gram, a survey by the Health and Welfare Ministry revealed Monday.
If a 4 kg or 5 kg baby, for example, consumes 120 grams of breast milk per kg of body weight, the baby would take in about 100 picograms of dioxin a day, health officials said. This is about 25 times the ministry-set tolerable daily intake of 4 picograms.
One picogram is one-trillionth of a gram.
However, the ministry said it is not hazardous if a baby takes in this amount of dioxin because the breast milk feeding period lasts less than a year and cannot be compared with lifelong intake.
Health officials also said there was no evidence that dioxin intake has affected the health of breast-fed babies.
The survey covered 415 women in 21 districts who gave birth to their first child last year and who breast-fed their babies.
By region, mothers in Shimane Prefecture had the highest average concentration of 29.5 picograms, while those in Okinawa Prefecture had the least, with 13.4 picograms.